Fluorinated ethoxylates are useful as surfactants in various applications. Commercially available fluorinated ethoxylates generally contain perfluoroalkyl terminal chains. Honda, et al. in, “Molecular Aggregation Structure and Surface Properties of Poly(fluoroalkylacrylate) Thin Films”, Macromolecules (2005), 38(13), 5699-5705, discusses the effect of chain length on efficacy of surface modification behaviors. For perfluoroalkyl compounds having eight or more carbons, the backbone of the polymer is in a parallel configuration. For perfluoroalkyl compounds having fewer perfluoroalkyl carbons, the compounds undergo reorientation. This reorientation decreases or eliminates the ability for exhibiting effective surface properties. Due to the high cost of producing long chain perfluoroalkyls, shorter chain perfluoroalkyls that can deliver the same or better performance are desired.
It is also desired to have fluorinated surfactants that demonstrate low foaming in use and have quicker foam disintegration, and are also stable in acidic, basic or brine solutions. Such solutions are used in applications such as cleaners, photovoltaic etching, and oil field drilling, stimulating, and other subterranean operations. Many surfactants known for low foaming, such as phosphates, are not stable in acidic, basic or brine formulations.
U.S. Pat. No. 5,597,874 discloses a coating composition comprising a) a perfluorinated acrylic polymer and b) a partially reacted fluorinated ethoxylated organic polyisocyanate crosslinking agent containing free isocyanate groups for use in clear coats over pigmented base coat.
It is desirable to have short chain perfluorinated ethoxylated compounds for use as surfactants, particularly in floor polishes and finishes, and in oil field applications. It is also desirable that such surfactants exhibit fast foam disintegration and be stable in acidic, basic or brine solutions. The present invention meets these needs.